In general, Polyimide has been widely used in various technical fields because it exhibits excellent high-temperature resistance, excellent chemical-resistance properties, high insulation, and high mechanical strength. Unfortunately, PI is difficult to dissolve in common solvents, because of its non-polar groups, such as aromatic rings and imino groups. However, close packing of molecular backbones causes difficulty in industrial manufacturing processes of PI and some problems in application. Therefore, thermoplastic polyimide (TPI) has been developed. Determining the performance of PI due to the monomer structure, some soft groups were usually introduced into TPI. However, for subsequent processing at high temperatures, it may lead to change in its structure and thermal properties, which reduce the heat resistance of the polymer and affect the performance thereof.
Accordingly, a novel PI monomer to meet the requirements of thermoplastic ability and heat-resistance is called-for.